#ifndef MBED_INTERRUPTMANAGER_H
#define MBED_INTERRUPTMANAGER_H

#include "cmsis.h"
#include "CallChain.h"
#include <string.h>

namespace mbed {

    /** Use this singleton if you need to chain interrupt handlers.

        Example (for LPC1768):
        @code
        #include "InterruptManager.h"
        #include "mbed.h"

        Ticker flipper;
        DigitalOut led1(LED1);
        DigitalOut led2(LED2);

        void flip(void) {
           led1 = !led1;
        }

        void handler(void) {
           led2 = !led1;
        }

        int main() {
           led1 = led2 = 0;
           flipper.attach(&flip, 1.0);
           InterruptManager::get()->add_handler(handler, TIMER3_IRQn);
        }
        @endcode
    */
    class InterruptManager {
      public:
        /** Return the only instance of this class
        */
        static InterruptManager* get();

        /** Destroy the current instance of the interrupt manager
        */
        static void destroy();

        /** Add a handler for an interrupt at the end of the handler list

            @param function the handler to add
            @param irq interrupt number

            @returns
            The function object created for 'function'
        */
        pFunctionPointer_t add_handler(void (*function)(void), IRQn_Type irq) {
            return add_common(function, irq);
        }

        /** Add a handler for an interrupt at the beginning of the handler list

            @param function the handler to add
            @param irq interrupt number

            @returns
            The function object created for 'function'
        */
        pFunctionPointer_t add_handler_front(void (*function)(void), IRQn_Type irq) {
            return add_common(function, irq, true);
        }

        /** Add a handler for an interrupt at the end of the handler list

            @param tptr pointer to the object that has the handler function
            @param mptr pointer to the actual handler function
            @param irq interrupt number

            @returns
            The function object created for 'tptr' and 'mptr'
        */
        template<typename T>
        pFunctionPointer_t add_handler(T* tptr, void (T::*mptr)(void), IRQn_Type irq) {
            return add_common(tptr, mptr, irq);
        }

        /** Add a handler for an interrupt at the beginning of the handler list

            @param tptr pointer to the object that has the handler function
            @param mptr pointer to the actual handler function
            @param irq interrupt number

            @returns
            The function object created for 'tptr' and 'mptr'
        */
        template<typename T>
        pFunctionPointer_t add_handler_front(T* tptr, void (T::*mptr)(void), IRQn_Type irq) {
            return add_common(tptr, mptr, irq, true);
        }

        /** Remove a handler from an interrupt

            @param handler the function object for the handler to remove
            @param irq the interrupt number

            @returns
            true if the handler was found and removed, false otherwise
        */
        bool remove_handler(pFunctionPointer_t handler, IRQn_Type irq);

      private:
        InterruptManager();
        ~InterruptManager();

        // We declare the copy contructor and the assignment operator, but we don't
        // implement them. This way, if someone tries to copy/assign our instance,
        // he will get an error at compile time.
        InterruptManager(const InterruptManager&);
        InterruptManager& operator =(const InterruptManager&);

        template<typename T>
        pFunctionPointer_t add_common(T* tptr, void (T::*mptr)(void), IRQn_Type irq, bool front = false) {
            int irq_pos = get_irq_index(irq);
            bool change = must_replace_vector(irq);

            pFunctionPointer_t pf = front ? _chains[irq_pos]->add_front(tptr, mptr) : _chains[irq_pos]->add(tptr, mptr);
            if (change) {
                NVIC_SetVector(irq, (uint32_t)&InterruptManager::static_irq_helper);
            }
            return pf;
        }

        pFunctionPointer_t add_common(void (*function)(void), IRQn_Type irq, bool front = false);
        bool must_replace_vector(IRQn_Type irq);
        int get_irq_index(IRQn_Type irq);
        void irq_helper();
        void add_helper(void (*function)(void), IRQn_Type irq, bool front = false);
        static void static_irq_helper();

        CallChain* _chains[NVIC_NUM_VECTORS];
        static InterruptManager* _instance;
    };

} // namespace mbed

#endif

